Pump-probe coupling of matter wave packets to remote lattice states

TL;DR

This paper demonstrates a novel method for coherently manipulating ultra-cold atom wave packets using pump-probe techniques to control their state and position within an optical lattice, advancing quantum control capabilities.

Contribution

It introduces a new experimental approach for controlling matter wave packets in optical lattices via pump-probe coupling, enabling long-distance quantum state manipulation.

Findings

Observation of wave packet reflection on a band gap

Resonant de-excitation into localized lattice states over 100 sites

Controlled quantum state preparation for quantum metrology

Abstract

The coherent manipulation of wave packets is an important tool in many areas of physics. We demonstrate the experimental realization of quasi-free wave packets of ultra-cold atoms bound by an external harmonic trap. The wave packets are produced by modulating the intensity of an optical lattice containing a Bose-Einstein condensate. The evolution of these wave packets is monitored in-situ and their reflection on a band gap is observed. In direct analogy with pump-probe spectroscopy, a probe pulse allows for the resonant de-excitation of the wave packet into localized lattice states at a long, controllable distance of more than 100 lattice sites from the main component. This coherent control mechanism for ultra-cold atoms thus enables controlled quantum state preparation, opening exciting perspectives for quantum metrology and simulation.